I wonder if [Flip Saunders] ever saw Isiah Thomas. He had a very disarming smile, says Christopher Peterson, a professor of psychology at the University of Michigan.

That smile didn't seem like a hindrance to the Hall of Fame point guard as he led his Detroit Pistons to the NBA championship twice (1989 and 1990); played in the NBA All Star game a dozen times and was named MVP both there (1984 and 1986) and in the NBA finals (1990).

In fact, if anything, speculates Mr. Peterson, the smile befuddledhis opponents, perhaps indicating that Mr. Thomas knew something they didn't, that a winning pass was right around the corner.

Smiling has also been shown to relax the body and mind, which is of particular interest to professional athletes, says sports psychologist Charlie Brown (www.fps- performance.com).

I encourage my athletes to smile, says Mr. Brown, who holds a doctorate in psychology. When you smile, it can trigger a different physiological state.

As strange as it might sound, that different physiological state of calm and relaxation is what helps an athlete get into the zone, says Mr. Brown, who also agrees that smiling screws with your opponent'shead.

Smiling in the general population too can have very positive outcomes, says Mr. Peterson, a co-founder of positive psychology, a branchof psychology that studies positive emotions and their effects on individuals, communities and institutions.

Smiles are a reflection of happiness, Mr. Peterson says. And research shows that happy workers are better workers, happy spouses are better spouses.

Not only that but smiles and happiness can be contagious. In otherwords, smiling not only helps the smilers, but also cheers up peoplearound them.

To test the hypothesis and to spread their own kind of cheer in tough times two Purdue University students, Brett Westcott and Cameron Brown, sponsored by Kodak, went on a nationwide tour called the Brightside Tour (www.brightside tour.com).

In late July, for example, they were in the nation's capital spreading free smiles and giving free compliments to strangers.

It's a great feeling, you give a smile and you receive one back, says Mr. Westcott. Smiling is definitely contagious.

Laughter Yoga (www.laughteryoga.org), developed in India in the mid-1990s, takes it a step further. It combines unconditional laughter with yogic breathing in a group setting. The idea is that the simulated laughter becomes real and contagious, triggering both mental and physical benefits, including a reduction in cortisol (stress hormone) and blood pressure.

Yet, in sports, the trend seems to be moving in the other direction: Smiling is out, and snarling and frowning are in.

I think it's becoming the norm, says Mr. Peterson, adding that he fails to see any benefits. If a happier worker is a more productive worker, why wouldn't that be true for athletes too?

I think it's pretty bad advice, because if you're telling the player not to smile, you're telling him not to be happy, he says. Which means you're reducing his ability to succeed.

The emphasis should be on promoting a good work ethic, not on excelling in frowning and snarling, he says and adds - while laughing - Maybe we should send Flip to a laughing club.

CAPTION(S):

Former NBA Basketball player Isiah Thomas of the Detroit Pistons has a disarming smile. According to some studies, smiling helps peopleto succeed. [NO CREDIT]

Nick Young of the Washington Wizards was recently admonished by head coach Flip Saunders for smiling too much. But some studies suggestsmiling can be a tool against opponents. [Photo by Peter Lockley/TheWashington Times]